Method and system for fast starting combustion engine in multi-engine aircraft

Abstract

The invention relates to a method and system for quickly starting a combustion engine in a multi-engine aircraft. The starter generator (FSG) comprises a first multi-phase winding (61) and a second multi-phase winding (62) which jointly operate the driveshaft (600) in a starting mode, the starting and power generation system (55) comprises a first main power source (65) and a second main power source (DCGEN), the first main power source (65) is connected to at least one first main electrical converter (68) electrically connected to the first winding (61) according to a command through a first electrical connection (66), and the second main power source (DCGEN) is connected to at least one second main electrical converter (68) electrically connected to the second winding (62) through a second electrical connection (66). The second main power source (DCGEN) is connected, on command, to at least one second main electrical converter (72) electrically connected to the second winding (62) by means of a second electrical connection (71).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of FR 2403318, filed on March 29, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to a method and a system for rapidly starting combustion engines in a multi-engine aircraft.

[0004] An aircraft may include a plurality of combustion engines for operating mechanical systems, and for example, mechanical systems that rotate at least one rotor on a helicopter.

[0005] The combustion engine may take the form of a turboshaft engine, possibly with a free turbine. A free turbine turboshaft engine comprises a gas generator provided with a compressor, a combustion chamber, and a high-pressure expansion assembly constrained to rotate with the compressor. The compressor may be provided with one or more compression stages. Similarly, the expansion assembly may include one or more expansion turbines. In addition, a free turbine turboshaft engine comprises at least one so-called "free" low-pressure working turbine that rotates the power shaft, i.e., a turbine that rotates mechanically independently of the compressor of the high-pressure expansion assembly.

[0006] Furthermore, the powerplant includes an engine starting system equipped with a starter-generator. The starter-generator comprises an electric motor mechanically connected to the moving components of the associated engine. In the case of a turboshaft engine, the electric motor comprises a shaft constrained to rotate together with the compressor and high-pressure expansion assembly of the gas generator.

[0007] This electric machine can operate in both electric motor mode and generator mode. When in electric motor mode, the electric machine converts the electrical power received from a source into mechanical energy in order to contribute to the operation of the mobile components of the associated combustion engine, for example during the starting phase. When in generator mode, the electric machine converts the mechanical energy drawn from the associated combustion engine into electrical power that can be transmitted to the aircraft's electrical grid.

[0008] Thus, a rotorcraft may comprise a power plant having a plurality of combustion engines for operating a power transmission system that in particular rotates at least one rotary wing.

[0009] The powerplant may optionally be operated in an asymmetric operating mode by placing one engine in standby during certain phases of operation of the aircraft.

[0010] In a rotorcraft, during the asymmetric mode, at least one active engine is regulated to ensure rotation of the rotor wing by generating a non-zero active drive power via its power shaft. At least one passive engine, on the other hand, is placed in a standby state, for example by being shut down or regulated via its power shaft to generate an idle power lower than the active drive power. Fuel may be supplied to the combustion chamber of the passive engine, or it may not be supplied to the combustion chamber of the passive engine. The passive engine is also asynchronous with the rotor wing via the flywheel.

[0011] In this asymmetric mode, if a fault occurs and that fault causes the active engine to stop, the backup engine must be reactivated quickly.

[0012] Therefore, the starter generator is designed to achieve reasonable start times at standard availability levels during the initial start of a combustion engine on the ground, and fast start times at high availability levels for reactivating a standby engine.

[0013] The combination of constraints on the starting time and constraints on the voltage value of the power grid supplying the electric machine can result in a starting system with a non-negligible mass. Background Art

[0014] Document FR3121293 describes a power plant equipped with a combustion engine and an electric starter. The power plant also has a primary power source, which may include a battery, and an auxiliary power source, which may also include a battery. Therefore, a connector electrically connects the primary and auxiliary power sources in series with the electric starter during the rapid starting phase.

[0015] Document FR3019214 discloses a starting system electrically independent of an onboard electrical network for starting two turboshaft engines of an aircraft. According to one embodiment, the starting system includes a first electric motor connected to the first turboshaft engine and a second electric motor connected to the second turboshaft engine. The first electric motor is electrically connected to a first DC-to-AC converter via a first electrical connector and to a second DC-to-AC converter via a second electrical connector. Similarly, the second electric motor is electrically connected to the first converter via a third electrical connector and to the second converter via a fourth electrical connector. The first converter is also electrically connected to a first power source via a first DC bus, and the second converter is electrically connected to a second main power source via a second DC bus.

[0016] Document US2021 / 071583A1 describes an engine comprising a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, and a low-pressure turbine. The high-pressure compressor, high-pressure turbine, and associated interconnecting shafts together form part of a high-pressure assembly. Similarly, the low-pressure compressor, low-pressure turbine, and associated interconnecting shafts form part of a low-pressure assembly. Furthermore, the engine comprises a first rotating electric machine mechanically coupled to the high-pressure assembly and a second rotating electric machine mechanically coupled to the low-pressure assembly.

[0017] Document US Pat. No. 7,513,119 B2 is also known. Summary of the Invention

[0018] The object of the present invention is therefore to provide an innovative starting and power generation system for a multi-engine aircraft, which optionally enables reasonable engine starting times to be obtained at a standard availability level when initially starting a combustion engine on the ground and / or fast starting times to be obtained at a high availability level for reactivating a standby engine when an asymmetric operating mode is applied.

[0019] The present invention therefore relates to a starting and power generation system for a main combustion engine of an aircraft, comprising a starter-generator provided with a transmission shaft, the starter-generator being able to operate in a motor mode for operating a main moving component of the main engine using the transmission shaft, and in a generator mode for operating the transmission shaft via the main moving component to generate electricity.

[0020] The starter generator includes a multi-phase first winding and a multi-phase second winding, the first winding and the second winding generate a magnetic field to generate corresponding motor torque, and the motor torque jointly causes the transmission shaft to operate in the starting mode of the motor mode. The starting and generating system includes a first main power supply and a second main power supply, the first main power supply is connected to at least one first main power converter electrically connected to the first winding through a first electrical connector according to a command, and the second main power supply is connected to at least one second main power converter electrically connected to the second winding through a second electrical connector according to a command.

[0021] The first polyphase winding and the second polyphase winding are components of a polyphase coil. Thus, the first polyphase winding and the second polyphase winding each comprise several electrical coils.

[0022] Consequently, the starter generator is powered during starting mode by two reversible DC-to-AC electrical converters, i.e., directly and without electrical connection / disconnection components. Upon command, the two converters are connected via electrical connection / disconnection components to two separate and independent power sources. These power sources may already be present on a standard aircraft and may not generate additional mass.

[0023] Furthermore, the use of two windings powered in parallel, or even independently, depending on the variant, allows the electromagnetic torque generated to be summed up for driving the transmission shaft. Consequently, the transmission shaft can generate a significant amount of mechanical power. This significant mechanical power allows for rapid starting of the main engines, i.e., in less than 10 seconds, for example. This rapid start is particularly advantageous in flight when the main engines are in standby mode in a multi-engine aircraft, such as when using the aforementioned asymmetric mode.

[0024] In the event of a fault in one of the power lines supplying the first and second windings, the remaining power line and the remaining winding provide sufficient mechanical power to start the main engine in reduced mode. This fault could be a sudden electrical short, such as a direct short between winding phases. This system is therefore safe and offers the possibility of starting the engine with a high level of availability, especially in flight.

[0025] In fact, each winding is dimensioned so as to obtain mechanical power alone allowing the main engine to start even in the presence of a braking torque generated by another winding due to, for example, a short-circuit current between its phases.

[0026] Thus, the starting and generating system uses two separate, isolated power sources to power the starter generator during starting, which may be of different types and / or already used elsewhere on the aircraft. This architecture enables a compromise between restart time, quality, and reliability to be achieved that is favorable for the target functionality.

[0027] The starting and generating machine may be a pure starter that can only be operated in motor mode, for example to start a high power engine that requires significant mechanical power.

[0028] The starting and generating system can also generate electricity during the power production mode by converting the mechanical power obtained from the running main engine. The starter generator can then become a voltage regulated source, for example 28 volts. In this operating mode, two electrical converters are used in parallel to use the entire available copper volume (i.e. the copper volume of the first and second windings) and thus optimize the quality of the system.

[0029] Optionally, the two electrical converters are used to supply power to two separate power grids, respectively. According to an example, the two electrical converters supply power to the normal power grid and the emergency power grid.

[0030] According to another example, two electrical converters supply two separate networks at different voltages, for example, one electrical converter supplies a 28 volt electrical network and the other electrical converter supplies a 56 volt electrical network, for example, to power flight control actuators.

[0031] The starting and power generation system may also have one or more of the following features.

[0032] According to one possibility, the first winding and the second winding may be different, for example by having windings with different numbers of turns resulting in different inductances.

[0033] Thus, each winding may be adapted to the associated mains power supply, in particular if the mains supplies are different and / or have different characteristics, such as a different voltage.

[0034] According to a possibility compatible with the aforementioned possibility, the first main power supply may not be voltage regulated and the second main power supply may be voltage regulated, or the first main power supply and the second main power supply may be regulated at different voltages.

[0035] These two alternatives enable control of the motor torque delivered to the main electric machine.

[0036] According to a possibility compatible with the aforementioned possibility, the first primary power source may comprise at least one battery or a thermal battery or a supercapacitor.

[0037] The primary power supply may include several of these unregulated electrical energy storage devices, thereby avoiding the need to oversize the electrical energy storage devices to support starting.

[0038] Such batteries are usually present on board aircraft.

[0039] According to a possibility compatible with the preceding one, the second primary power source may comprise a voltage-regulated generator configured to be operated mechanically by means of a mechanical system.

[0040] Such a generator is usually present on board an aircraft.

[0041] According to a first alternative of the starter generator, the starter generator may include an electric machine having a stator provided with a first winding and a second winding, the first winding and the second winding being multi-phase, having a floating neutral and being electrically insulated from each other, the electric machine including a rotor with embedded permanent magnets, the rotor having variable reluctance and being constrained to rotate with the drive shaft.

[0042] The use of two windings powered in parallel allows the electromagnetic torque generated by the embedded permanent magnet rotor with variable reluctance to be combined. In the event of a fault in one of the power lines supplying the two stator windings, the use of a rotor with embedded permanent magnets and variable reluctance limits the short-circuit current that could otherwise occur. This motor reduces short-circuit current at high speeds, thereby limiting the braking torque and heating of the motor that would result in an internal short circuit. Consequently, the other power line and the other stator winding provide sufficient mechanical power to start the main engine in step-down mode. Consequently, the starter-generator is robust and highly reliable.

[0043] According to a second alternative of the starter generator, the starter generator may include a dual motor with separate excitation, the dual motor with separate excitation including a stator provided with a first winding and a second winding, the dual motor with separate excitation including a rotor provided with two rotor windings electrically connected to a brush commutator.

[0044] The two rotor windings are coordinated with the first and second stator windings, respectively. Internal short-circuit events are managed by deactivating the associated excitation, eliminating the braking torque caused by the short circuit. This results in a highly reliable starter-generator.

[0045] According to a third alternative of the starter generator, the starter generator can include a magnetic starter and an electric machine operating in generator mode and motor mode, the magnetic starter being provided with a first stator and a first rotor, the first stator having a first winding, the first rotor being mechanically connected to the transmission shaft via a flywheel, the electric machine comprising a second stator and a second rotor, the second stator being provided with a second winding, the second rotor being integral with the transmission shaft, the electric machine being able to be an electric machine with separate excitation or asynchronous excitation.

[0046] Therefore, the starter is used only during the starting phase, while the motor is used both during the starting phase and during power generation mode. The flywheel isolates the starter from the motor in the event of a short circuit in one of these components. In the case of a separately excited motor, disconnecting the excitation eliminates any potential short circuit. This results in a highly reliable starter-generator.

[0047] According to a fourth alternative of the starter generator, the starter generator may comprise a double asynchronous machine comprising a stator provided with a first winding and a second winding.

[0048] Internal short circuits are managed by taking into account the internal residual voltage of the machine.

[0049] According to a fifth alternative of the starter generator, the starter generator may include a separately excited electric machine including a stator having one of the first and second windings, and an asynchronous machine including a stator having the other of the first and second windings.

[0050] Whatever the nature of the starter-generator, according to one possibility compatible with the aforementioned, the starting and generating system may comprise a manager configured to:

[0051] In a starting mode, the first winding is powered by at least a first main power source via a first main power converter, and the second winding is powered by at least a second main power source via a second main power converter;

[0052] in a standby mode, powering one of the first and second windings with a second main power source, the first main power source being kept under load via a transverse electrical connection to the second electrical connection; and

[0053] In the power production mode, the second main power converter is electrically connected in parallel with the first main power converter to supply power to the first main power source.

[0054] The term "manager" refers to a system for performing the various actions described above. The manager may include at least one electrical center, electronics for starting a generator, a computer, contactors controlled to open or close electrical connections, and the like.

[0055] According to one possibility compatible with the preceding one, the second electrical connection may comprise a main bus and the manager may comprise:

[0056] Controller;

[0057] a first main contactor, commanded by the controller and arranged on the first electrical connection; and

[0058] • A second main contactor, commanded by the controller and arranged on a second electrical connection between the main bus and the second main electrical converter.

[0059] The first contactor and the second contactor enable the main electrical converter to be electrically connected to the main power supply when necessary.

[0060] Optionally, the manager may include:

[0061] a third main contactor, commanded by the controller and arranged between the main bus and a connection configured to be electrically connected to a complementary electrical connection of an additional circuit;

[0062] a fourth main contactor, commanded by the controller and arranged on a transverse electrical connection extending from the second electrical connection to the first electrical connection between the first main contactor and the first main power source; and

[0063] A fifth main contactor, commanded by the controller and arranged on an electrical line connecting the first and second electrical connections firstly between the second main contactor and the second main electrical converter and secondly between the first main contactor and the first main electrical converter.

[0064] Such various contactors enable the various operating modes described above.

[0065] According to one variant, a third main contactor is arranged on the second electrical connection, and the additional contactor can be arranged between the third main contactor and the second electrical power source.

[0066] According to another variant enabling the parallel placement of the main power sources, an additional electrical connector connects the first electrical connector and the second electrical connector. The additional electrical connector is connected to the second electrical connector between the second main power source and the main bus, and is connected to the first electrical connector between the first main power source and the first main contactor. Furthermore, the first electrical connector includes an additional contactor between its connection to the additional electrical connector and its connection to the transverse electrical connector.

[0067] According to a possibility compatible with the aforementioned possibility, the first main power supply and the second main power supply may have different voltages.

[0068] The invention also relates to an aircraft provided with a main combustion engine and at least one additional combustion engine connected to a mechanical system that operates at least one rotating wing or one rotor or one propeller, the additional engine being connected to an additional electric motor capable of operating according to a motor mode for operating an additional mobile assembly of the additional engine and a generator mode for generating electrical power by operating said additional mobile assembly, the additional electric motor being electrically connected to an additional electrical converter that is connected to an additional electrical power source via an additional electrical connection.

[0069] The aircraft comprises a starting and power generation system of the type described above for the main engines.

[0070] According to one possibility, the mechanical system may comprise a gearbox connected to the main engine and the additional engine, and the second main power source may be operated via the gearbox.

[0071] For example, the gearbox may be mechanically connected to the rotating airfoil and / or propeller and / or rotor for controlling yaw motion.

[0072] Furthermore, the invention relates to a method for starting a combustion engine and generating electricity using a starting and power generation system of the type described above.

[0073] The method includes:

[0074] a start-up mode comprising the steps of: supplying power to the first winding using at least a first main power source via a first main power converter, and supplying power to the second winding using at least a second main power source via a second main power converter;

[0075] a standby mode comprising the steps of: powering one of the first and second windings with a second main power source, keeping the first main power source under load via a transverse electrical connection to the second electrical connection; and

[0076] • An electricity production mode comprising the steps of: connecting the second main electrical converter electrically in parallel with the first main electrical converter and connecting them to the first main power source. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The invention and its advantages will emerge in more detail from the following description of examples given by way of illustration with reference to the accompanying drawings, in which:

[0078] Figure 1 The starting and power generation system for the main engine when stationary is shown;

[0079] Figure 2 An example of a starter generator according to the present invention is shown;

[0080] Figure 3 An example of a starter generator according to the present invention is shown;

[0081] Figure 4 An example of a starter generator according to the present invention is shown;

[0082] Figure 5 shows the start-up mode during Figure 1 Starting and power generation systems;

[0083] Figure 6 shows the standby mode during Figure 1 Starting and power generation systems;

[0084] Figure 7 shows the power generation mode during Figure 1 Starting and power generation systems;

[0085] Figure 8 shows a starting and generating system with parallel power sources during standby mode;

[0086] Figure 9 shows the start-up mode during Figure 8starting and generating systems; and

[0087] Figure 10 shows the power generation mode during Figure 8 Starting and power generation systems. DETAILED DESCRIPTION

[0088] Elements that appear in more than one figure are given the same reference numeral in each of the figures.

[0089] Figure 1 A starting and power generation system 55 for the main combustion engines 11 of the aircraft 1 is shown.

[0090] Such an aircraft 1 thus comprises a power plant provided with a main engine 11 or even with at least one additional combustion engine 12. If it is necessary to identify a particular engine 10, reference numeral 10 denotes any combustion engine and reference numerals 11 and 12 denote the main engine and the additional engine, respectively.

[0091] The main engine 11 and any additional engine(s) 12 may optionally be controlled by respective engine regulation systems 101, 102. Each engine regulation system 101, 102 may be of a standard type and may therefore include a fuel metering device and various sensors connected to an engine computer configured to control the fuel metering device based at least on signals emitted by the one or more sensors. The engine regulation systems will not be described in greater detail in order to avoid complicating the present description; these engine regulation systems are well known to those skilled in the art.

[0092] According to one example, at least one engine 10 may be a turboshaft engine. For example, the main engine 11 comprises a turboshaft engine equipped with a gas generator 15. The gas generator 15 has at least one compression turbine 16, a combustion chamber 17 into which fuel is injected, and at least one expansion turbine 18 constrained to rotate together with the one or more compression turbines 16. The one or more compression turbines 16 are rotationally mechanically connected to the one or more expansion turbines 18 to form the main moving assembly 14. In addition, the turboshaft engine may include at least one free turbine 19 that directly or indirectly drives the engine's power shaft 21.

[0093] Similarly, the additional engine 12 may be a turboshaft engine provided with an additional moving assembly 140 and a power shaft 22. Reference numeral 20 denotes any power shaft, and reference numerals 21, 22 denote specific power shafts of the two engines 11, 12, respectively.

[0094] Thus, regardless of the type of engine, each engine 10 comprises a power shaft 20 and a moving assembly 14 , 140 .

[0095] Furthermore, one or more power shafts 20 are mechanically connected to a mechanical system 25 to operate them. For example, the mechanical system 25 can be connected to at least one aerodynamic rotating member 5. In particular, the aerodynamic rotating member 5 can be a rotating wing, a rotor for controlling yaw movement, or a propeller according to this example.

[0096] By way of illustration, the mechanical system 25 may include a gearbox 26 mechanically interposed between the engines 10 and the rotating wing 5. For example, the gearbox 26 includes a rotor main shaft 35 provided with one or more colinear shafts 36, 37 connected to the aerodynamic rotating member 5. The gearbox 26 may include one input shaft 30 for each engine 10 and various gears arranged between the input shafts 30 and the rotor main shaft 35. According to the example given by way of illustration, each input shaft 30 is coupled to a large wheel 40. This large wheel 40 is then mechanically coupled to a sun gear 46 of a power reduction stage 45 via an inner shaft 41. Planetary gears 47 are then coupled first to the sun gear 46 and to a ring gear 48, which is stationary in the reference frame of the aircraft 1. Furthermore, the planetary gears 47 are carried by a planet carrier 49, which is constrained to rotate with the rotor main shaft 35. Each input shaft 30 is then rotated directly by the power shaft 20 of the engine 10 or via a corresponding mechanical input gear train. The mechanical system 25 and, according to the example shown, the mechanical input gear train may comprise at least one flywheel 51 and / or at least one connecting shaft 52 and / or at least one connector allowing for misalignment, among other things.

[0097] The literature describes various types of gearboxes and various motion trains, the examples described being given by way of illustration only.

[0098] Independently of the nature of the mechanical system 25 and the presence or absence of one or more additional engines 12, the starting and generating system 55 includes a starter generator FSG capable of operating in a motor mode MOT for operating the main movable component 14 of the main engine 11 and in a generator mode GEN for generating electricity by operating the main movable component 14.

[0099] Thus, the starter generator FSG comprises a transmission shaft 600 connected to the main moving assembly 14 .

[0100] In addition, the starter generator FSG includes a first multi-phase winding 61 and a second multi-phase winding 62. The coils of the first winding 61 and the second winding 62 are electrically connected to the first main electric converter 68 and the second main electric converter 72, respectively.

[0101] When the first and second windings 61, 62 are energized, they generate a magnetic field that together rotate the drive shaft 600. Conversely, during the generator mode GEN, the drive shaft 600 is operated by the main moving assembly 14, which enables the generation of electricity.

[0102] The starter generator FSG allows for various operating modes, including: i) a starting mode MODRAP, in which the first and second windings 61, 62 are powered to rotate the transmission shaft 600 together; ii) a standby mode MODVEIL, in which only one of the first and second windings 61, 62 is powered to rotate the transmission shaft 600; and iii) a power production mode MODPROD, in which the first and second windings 61, 62 generate power via the main moving assembly 14 when the transmission shaft 600 is rotated by the main engine 11.

[0103] Figures 1 to 4 Various embodiments of the starter generator FSG are shown.

[0104] according to Figure 1 The starter generator FSG includes a motor 59 having a stator 60 provided with a first winding 61 and a second winding 62. The first winding 61 and the second winding 62 are, for example, three-phase, have a floating neutral line, and are electrically isolated from each other. Furthermore, the motor 59 includes a rotor 64 having embedded permanent magnets 640, which has variable reluctance and is integral with the drive shaft 600. The permanent magnets 640 are embedded in the rotor 64.

[0105] according to Figure 2 In the exemplary embodiment of the present invention, the starter generator FSG includes a dual motor 110 with separate excitation. This dual motor 110 with separate excitation includes a stator 111 provided with a first winding 61 and a second winding 62. Furthermore, the dual motor 110 with separate excitation includes a rotor 112 provided with two rotor windings facing the first winding 61 and the second winding 62. These two rotor windings are electrically connected to two additional converters 113 and 114 via a brush commutator 115. These two additional converters 113 and 114 are electrically connected in parallel with the first main converter 68 and the second main converter 72, respectively.

[0106] according to Figure 3In the exemplary embodiment of the invention, the starter generator FSG comprises a conventional magnetic starter 120 and an electric machine 125 operating in generator mode and motor mode. The magnetic starter 120 is then provided with a first stator 121 and a first rotor 122, the first stator 121 having a first winding 61, the first rotor 122 being provided with at least one permanent magnet and being mechanically connected to the transmission shaft 600, in particular via a flywheel 123 or even via an electric machine 125. This electric machine 125 comprises a second stator 126 provided with a second winding 62 and a second rotor 127 integral with the transmission shaft 600, the electric machine 125 being optionally Figure 2 Separately excited motors or asynchronous motors of the type shown.

[0107] During the starting mode MODRAP, the magnetic starter 120 and the electric motor 125 together set the drive shaft 600 in motion. In the event of a failure of one of these two components, the other ensures starting.

[0108] During the standby mode MODVEIL, only the electric motor 125 is used, for example, to operate the drive shaft 600 .

[0109] During the electricity production mode MODPROD, only the electric motor 125 generates electricity. Then, the magnetic starter 120 is disconnected from the transmission shaft 600 via the flywheel 123.

[0110] Variations of this embodiment include a separately excited electric machine including a stator having one of a first winding and a second winding, and an asynchronous electric machine including a stator having the other of the first winding and the second winding.

[0111] according to Figure 4 In the exemplary embodiment of the present invention, the starter generator FSG includes a dual asynchronous motor 130. The dual asynchronous motor 130 includes a stator 131 provided with a first winding 61 and a second winding 62. In addition, the dual asynchronous motor 130 includes a rotor 132 integral with the transmission shaft 600. The rotor 132 may be a type known as a "squirrel cage rotor."

[0112] Regardless of the embodiment of the starter generator FSG and referring to Figure 5 The system 55 may include an additional circuit comprising an additional electric motor SG connected to the additional engine 12, for example, of the same type as the main motor or a standard type. The additional electric motor SG may include an additional electric motor 590 connected to an additional converter 591. The additional converter 591 may be connected to an additional power source 95 via an additional electrical connection 98. For example, the additional power source 95 may include at least one battery, a thermal battery, or a supercapacitor. Optionally, the additional power source 95 may be connected to an additional basic onboard power grid 304 that supplies power to one or more consumers.

[0113] In general, the terms "electrical connector" and "wire" refer to an assembly that may include at least one wire or track, at least one electrical contact, at least one electrical bus, and the like.

[0114] For example, the additional electrical connections 98 include an additional electrical center EMB2. This additional center EMB2 includes an additional bus 971 connected to the additional converter 591 by a first additional contactor K25 and to the additional power source 95 by a second additional contactor K22. Additional bus 971 can be connected to a complementary electrical connection 88, which is connected to a circuit that cooperates with the starter generator FSG. This complementary electrical connection 88 is equipped with a third additional contactor K23. Finally, additional bus 971 can be connected to the auxiliary power grid 302 of the aircraft 1. Additional contactors K22, K23, and K25 are controlled by the conventional electronics of the additional electrical center EMB2.

[0115] Regardless of the embodiment of the starter generator FSG and regardless of the possible presence of additional circuits, the starting and power generation system 55 comprises a first main power source 65. The first main power source 65 is connected on command to at least a first main electrical converter 68 via a first electrical connection 66. Optionally, the first main power source 65 is connected to the main basic onboard electrical network 303 that supplies one or more consumers.

[0116] Furthermore, the starting and power generation system 55 comprises a second main power source DCGEN which is connected on command to at least a second main power converter 72 via a second electrical connection 71. Optionally, the second main power source DCGEN is connected to two primary and additional onboard electrical networks 303, 304.

[0117] For example, the second main power supply DCGEN is voltage regulated. Thus, according to the example shown, the second main power supply DCGEN may comprise a generator coupled to the mechanical system 25 and possibly to the gearbox 26 or even to a shaft integral with the large wheel 40 .

[0118] Optionally, no voltage regulation is performed on the first main power source 65. For example, the first main power source 65 comprises a battery or a thermal battery or a supercapacitor.

[0119] Alternatively, the first main power source 65 and the second main power source DCGEN may be regulated at different voltages.

[0120] The first electrical connection 66 and the second electrical connection 71 may pass through the main electrical center EMB1 .

[0121] According to another aspect, the starting and power generation system 55 may comprise a manager 75 configured to apply the method according to the invention to start the combustion engine and generate electrical power.

[0122] The manager 75 may include a controller 76. The controller 76 may include at least one processor for applying the method of the present invention via a software program and logic circuits or equivalent. The at least one processor may include one of the following elements: a computer dedicated or not dedicated to this application, the first electronic device 107 of the main electrical center EMB1, the second electronic device 106 of the starter generator FSG, and / or a computer of the engine control system 101, 102.

[0123] In addition, the manager 75 may include a human-machine interface 105 that enables the pilot of the aircraft 1 to select an operating mode to be applied, such as the start mode MODRAP, the standby mode MODVEIL, or even the power generation mode MODVEIL. For example, the human-machine interface 105 is connected to the controller 76 by wire or wirelessly. Alternatively, the human-machine interface 105 may include a touch panel screen, buttons, a keyboard, etc.

[0124] Optionally, the manager 75 may include at least one operating sensor that monitors the operation of the main motor FSG and transmits a measurement signal to the controller 76. For example, the at least one operating sensor includes a sensor for measuring position, a sensor for measuring current, and a sensor for measuring temperature. The redundancy and dissimilarity of these sensors can ensure nominal operation of the main motor FSG in the event of a failure of one or more of these sensors.

[0125] Furthermore, the controller 76 can execute instructions for operating the first and second main electrical converters 68, 72, depending on the mode being used. In motor mode, at least one of the first and second main electrical converters 68, 72 generates a multi-phase voltage with variable amplitude and frequency, which is controlled to ensure control of the generated motor torque. The first and second main electrical power sources 65, DCGEN can generate different voltage values, which means that the control of the first and second main electrical converters 68, 72 is asynchronous. However, in generator mode, the first and second main electrical converters 68, 72 are used in parallel and are synchronized.

[0126] In addition, the manager 75 may include a first main contactor K11, which is commanded by the controller 76 and is arranged on the first electrical connection 66 to electrically open or close the first electrical connection 66. For example, the first electrical connection 66 includes a first upstream wired connection 661 extending from the first main power source 65 to the first main contactor K11, and a first downstream wired connection 662 extending from the first main contactor K11 to the first main electrical converter 68. For convenience, the terms "upstream" and "downstream" are used to distinguish between electrical parts of the connection in a selected direction.

[0127] In addition, the manager 75 may include a second main contactor K15, which is commanded by the controller 76 and is arranged on the second electrical connection 71 to electrically open or close the second electrical connection 71. For example, the second electrical connection 71 includes a second upstream wired connection 711 extending from the second main power source DCGEN to the second main contactor K15, and a second downstream wired connection 712 extending from the second main contactor K15 to the second main electrical converter 72. Optionally, the second upstream wired connection 711 includes the main bus 671. The main bus 671 is connected to the second main contactor K15, or even to a connection to the first downstream wired connection 662, which itself is connected to the auxiliary onboard power grid 301.

[0128] Additionally, the manager 75 may include:

[0129] a third main contactor K13 commanded by the controller 76 and arranged between the main bus 671 and a connection 672 configured to be electrically connected to a complementary electrical connection 88 ;

[0130] a fourth main contactor K12 , which is commanded by the controller 76 and is arranged on a transverse electrical connection 96 extending from the second electrical connection 71 to the first electrical connection 66 between the first main contactor K11 and the first main power source 65 ;

[0131] a fifth main contactor KP, which is commanded by the controller 76 and is arranged on an electrical line connecting the first electrical connection 66 and the second electrical connection 71, firstly between the second main contactor K15 and the second main electrical converter 72, and secondly between the first main contactor K11 and the first main electrical converter 68 (i.e. between the first downstream wired connection 662 and the second downstream wired connection 712); and

[0132] ·Sixth contactor K14.

[0133] The various contactors mentioned may be of standard types for opening or closing electrical wires and may be commanded by the controller 76 in a standard manner.

[0134] For example, the first main contactor K11 , the second main contactor K15 , the third main contactor K13 , the fourth main contactor K12 and the sixth main contactor K14 belong to the main electrical center EMB1 and can be controlled by its electronics 107 , while the fifth main contactor KP belongs to the starter generator FSG and can be controlled by its electronics 106 .

[0135] exist Figure 5In a first variant, the first downstream line connection 662 comprises only line connections to the first main power source 65, the first main contactor K11 and the transverse electrical connection 96. In addition, the second upstream line connection 711 comprises a third main contactor K13 and a sixth contactor K14, which is arranged between the second power source DCGEN and the third main contactor K13.

[0136] Figures 5 to 7 The various operating modes of this first variant of the starting and power generation system 55 of the present invention are shown.

[0137] Figure 5 The first variant of the starting and power generation system 55 is shown during the starting mode MODRAP. The controller 76 is configured to power the first winding 61 exclusively using the first main power source 65 via the first main power converter 68 during step STPA1. Consequently, the controller 76 closes the first main contactor K11. For example, the additional engine 12 may be stopped or disconnected in parallel.

[0138] The controller 76 is also configured to power the second winding 62 during step STPA2 using only the second main power supply DCGEN via the second main electrical converter 72. Therefore, the controller 76 closes the second main contactor K15, the third main contactor K13 and the sixth contactor K14.

[0139] Then, the controller 76 is further configured to control the main electric motor FSG to operate in the motor mode.

[0140] The controller 76 is optionally further configured to open the fourth main contactor K12 and the fifth main contactor KP to isolate the first main power source 65 and the second main power source DCGEN.

[0141] Under these conditions, a rapid restart of the main engine 11 is obtained by using two different power sources 65, DCGEN to power the two electrical converters 68, 72 respectively.

[0142] Figure 6 The first variant of the starting and power generation system 55 is shown during a standby mode MODVEIL.

[0143] During this standby mode MODVEIL, the controller 76 is configured to power the second winding 62 solely using the second main power source DCGEN via the second main power converter 72 during step STPB1. Consequently, the controller 76 closes the second, third, and sixth main contactors K15, K13, and K14, and opens the first and fifth main contactors K11 and KP. The controller 76 is then further configured to control the main motor FSG to operate in the motor mode MOT, for example, to maintain the main moving assembly 14 at a predetermined rotational speed, with the combustion chamber 17 shut off or supplied with fuel. Concurrently, the auxiliary engine 12 can operate normally to operate the mechanical system 25, and the auxiliary motor SG can operate in the generator mode MODGEN.

[0144] The controller 76 is also configured to keep the first main power source 65 under load during step STPB2 by powering the first electrical connection 66 with the second main power source DCGEN. The controller 76 therefore closes the fourth main contactor K12.

[0145] Figure 7 The starting and power generation system 55 of a first variant is shown during the power production mode MODPROP.

[0146] During this power production mode MODPROP, the controller 76 is configured to electrically disconnect the second main power source DCGEN from the main motor FSG during a step STPC1 . The controller 76 thus opens the second main contactor K15 and the third main contactor K13 .

[0147] The controller 76 is also configured to electrically connect the second main electrical converter 72 to the first main electrical converter 68 in parallel during step STPC2, and connect them to the first main power source 65. Thus, the controller 76 closes the fifth main contactor KP and the first main contactor K11, and opens the fourth main contactor K12. The controller 76 optionally closes the sixth contactor K14 and the third additional contactor K23.

[0148] The controller 76 is then further configured to control the main electrical machine FSG to operate in generator mode GEN. The first and second main electrical converters 68 and 72 then deliver electrical power to the first main electrical connection 66. The second main electrical power source DCGEN supplies the basic onboard network 303 with electrical power.

[0149] Figures 8 to 10 A second variant is shown.

[0150] Compared with the first variant, the sixth contactor K14 is displaced. Figure 8The first upstream wired connection 661 comprises a sixth contactor K14 , and the transverse electrical connection 96 is connected to the first upstream wired connection 661 between the first main power source 65 and the sixth contactor K14 .

[0151] In addition, a third main contactor K13 is arranged between the main busbar 671 and the complementary electrical connection 88 .

[0152] Finally, between the sixth contactor K14 and the first main contactor K11, an intermediate wired electrical connection extends from the second upstream wired connection 711 to the first upstream wired connection 661. For example, the second upstream wired connection 711 includes a connection between the main bus 671 and the second main power supply DCGEN, which is connected to the transverse electrical connection 96 and the intermediate wired electrical connection.

[0153] exist Figure 8 During the illustrated standby mode MODVEIL, the controller 76 is configured to power the first winding 61 with the second main power supply DCGEN via the first main power converter 68. The controller 76 thus closes the first main contactor K11 and opens the second main contactor K15, the sixth contactor K14 and the fifth main contactor KP.

[0154] The controller 76 is further configured to control the main electric motor FSG to operate in the motor mode MOT, for example, to maintain the main moving assembly 14 at a predetermined rotational speed, with the combustion chamber 17 closed or fueled. In parallel, the auxiliary engine 12 can operate normally to operate the mechanical system 25, and the auxiliary electric motor SG can operate in the generator mode MODGEN.

[0155] The controller 76 is also configured to keep the first main power source 65 under load by powering the first electrical connection 66 with the second main power source DCGEN. Therefore, the controller 76 closes the fourth main contactor K12. Optionally, the controller 76 also closes the third main contactor K13.

[0156] Figure 9 A second variant of the starting and power generation system 55 is shown during a starting mode MODRAP. The controller 76 is configured to power the first winding 61 using the first main power source 65 and the second main power source DCGEN via the first main power converter 68, and to power the second winding 62 using the first main power source 65 and the second main power source DCGEN via the second main power converter 72.

[0157] Therefore, the controller 76 closes the first main contactor K11, the fourth main contactor K12 and the second main contactor K15. In parallel, the controller 76 opens the third main contactor K13, the sixth contactor K14 and the fifth main contactor KP.

[0158] Figure 10 A second variant of the starting and power generation system 55 is shown during the power production mode MODPROP.

[0159] During this power production mode MODPROP, the controller 76 is configured to electrically connect the second main electrical converter 72 in series with the first main electrical converter 68 and connect them to the first main power source 65. Similarly, the second main power source DCGEN can supply power to the auxiliary onboard power grid 301. Therefore, the controller 76 closes the fifth main contactor KP, the second main contactor K15, the sixth contactor K14, or even the third main contactor K13, and opens the fourth main contactor K12 and the first main contactor K11.

[0160] Thus, the auxiliary onboard electrical network 301 and the first main power source 65 may be powered by the converter 68 , the converter 72 and the second main power source DCGEN.

[0161] Naturally, the implementation of the present invention can be varied in many ways. Although several embodiments have been described above, it should be readily understood that it is not possible to identify all possible embodiments. Naturally, any of the described methods can be replaced with equivalents without exceeding the scope of the present invention and the claims.

Claims

1. A starting and power generation system (55) for a main combustion engine (11) of an aircraft (1), the starting and power generation system (55) comprising a starter generator (FSG) provided with a transmission shaft (600), the starter generator (FSG) being operable in a motor mode (MOT) and a generator mode (GEN), the motor mode (MOT) being used to operate a main moving assembly (14) of the main combustion engine (11) using the transmission shaft (600), the generator mode (GEN) being used to operate the transmission shaft (600) via the main moving assembly (14) to generate electricity, the starter generator (FSG) comprising a first multi-phase winding (61) and a second multi-phase winding ( 62), the first winding (61) and the second winding (62) generate a magnetic field to generate a corresponding motor torque, and the motor torque together causes the transmission shaft (600) to operate in a starting mode of the motor mode (MOT), and the starting and power generation system (55) includes a first main power supply (65) and a second main power supply (DCGEN), the first main power supply (65) is connected to at least one first main power converter (68) electrically connected to the first winding (61) through a first electrical connection (66) according to a command, and the second main power supply (DCGEN) is connected to at least one second main power converter (72) electrically connected to the second winding (62) through a second electrical connection (71) according to a command, wherein the starting and power generation system (55) includes a manager (75) configured to: In the starting mode (MODRAP), the first winding (61) is powered by at least the first main power source (65) via the first main power converter (68), and the second winding (62) is powered by at least the second main power source (DCGEN) via the second main power converter (72); in a standby mode (MODVEIL), powering one of the first winding (61) and the second winding (62) with the second main power source (DCGEN), keeping the first main power source (65) under load via a transverse electrical connection (96) connected to the second electrical connection (71); and In power production mode (MODPROD), the second main power converter (72) and the first main power converter (68) are electrically connected in parallel to supply power to the first main power source (65).

2. The starting and power generation system according to claim 1, The first main power supply (65) is not voltage regulated, while the second main power supply (DCGEN) is voltage regulated, or the first main power supply (65) and the second main power supply (DCGEN) are regulated to different voltages.

3. The starting and power generation system according to claim 1, The first main power source (65) comprises at least one battery, a thermal battery or a supercapacitor.

4. The starting and power generation system according to claim 1, The second main power source (DCGEN) includes a voltage-regulated generator configured to be mechanically started by a mechanical system.

5. The starting and power generation system according to claim 1, The starter generator (FSG) comprises an electric machine having a stator provided with a first winding (61) and a second winding (62), the first winding (61) and the second winding (62) being multi-phase, having a floating neutral line and being electrically insulated from each other, the electric machine comprising a rotor (64) having embedded permanent magnets, the rotor having variable reluctance and being constrained to rotate with the drive shaft.

6. The starting and power generation system according to claim 1, The starter generator (FSG) includes a dual motor (110) with separate excitation, the dual motor (110) with separate excitation includes a stator (111), the stator (111) is provided with the first winding (61) and the second winding (62), the dual motor (110) with separate excitation includes a rotor (112), and the rotor (112) is provided with two rotor windings electrically connected to a brush commutator (115).

7. The starting and power generation system according to claim 1, The starter generator (FSG) includes a magnetic starter (120) and an electric motor (125) operating in generator mode and motor mode, the magnetic starter (120) is provided with a first stator and a first rotor (122), the first stator has the first winding (61), the first rotor (122) is mechanically connected to the transmission shaft (600) through a flywheel (123), the electric motor includes a second stator (126) and a second rotor (127), the second stator (126) is provided with the second winding (62), the second rotor (127) is integrated with the transmission shaft (600), and the electric motor can be a motor with separate excitation or asynchronous excitation.

8. The starting and power generation system according to claim 1, The starter generator (FSG) includes a dual asynchronous motor (130), and the dual asynchronous motor (130) includes a stator provided with the first winding (61) and the second winding (62).

9. The starting and power generation system according to claim 1, The starter generator (FSG) includes a separately excited motor and an asynchronous motor, wherein the separately excited motor includes a stator having one of the first winding (61) and the second winding (62), and the asynchronous motor includes a stator having the other of the first winding (61) and the second winding (62).

10. The starting and power generation system according to claim 1, wherein the second electrical connection (71) comprises a main bus (671), and the manager (75) comprises: Controller (76); a first main contactor (K11) commanded by the controller (76) and arranged on the first electrical connection (66); and A second main contactor (K15) commanded by the controller (76) and arranged on the second electrical connection (71) between the main bus (671) and the second main electrical converter (72).

11. The starting and power generation system according to claim 10, wherein the manager (75) comprises: a third main contactor (K13) commanded by the controller (76) and arranged between the main bus (671) and a connector (672) configured to be electrically connected to a complementary electrical connector (88) of an additional circuit; a fourth main contactor (K12) commanded by the controller (76) and arranged on a transverse electrical connection (96) extending from the second electrical connection (71) to the first electrical connection (66) between the first main contactor (K11) and the first main power source (65); and a fifth main contactor (KP) commanded by the controller (76) and arranged on an electrical line connecting the first electrical connection (66) and the second electrical connection (71) firstly between the second main contactor (K15) and the second main electrical converter (72) and secondly between the first main contactor (K11) and the first main electrical converter (68).

12. An aircraft (1) provided with a main combustion engine (11) and at least one additional combustion engine (12) connected to a mechanical system (25) which operates at least one rotary wing (5) or one rotor or one propeller, the additional combustion engine (12) being connected to an additional electric motor (SG) capable of operating according to a motor mode (MOT) for operating an additional mobile assembly (140) of the additional combustion engine (12) and a generator mode (GEN) for generating electrical power by operating the additional mobile assembly (140), the additional electric motor (SG) being electrically connected to an additional electrical converter (FSG1) which is connected to an additional electrical power source (95) via an additional electrical connection (98), The aircraft comprises a starting and power generation system (55) according to claim 1 for a main combustion engine (11).

13. The aircraft according to claim 12, The mechanical system (25) comprises a gearbox (26) connected to the main combustion engine (11) and the additional combustion engine (12), and the second main power source (DCGEN) is started by the gearbox (26).

14. A method of starting a combustion engine and generating electricity using a starting and power generation system (55) according to claim 1, The method comprises: a start mode (MODRAP) comprising the steps of: supplying (STPA1) the first winding (61) with power via the first main power converter (68) using at least the first main power source (65), and supplying (STPA2) the second winding (62) with power via the second main power converter (72) using at least the second main power source (DCGEN); a standby mode (MODVEIL) comprising the steps of: supplying (STPB1) one of the first winding (61) and the second winding (62) with the second main power source (DCGEN) and keeping (STPB2) the first main power source (65) under load via a transverse electrical connection (96) connected to the second electrical connection (71); and • Power production mode (MODPROD) comprising the steps of connecting the second main electrical converter (72) and the first main electrical converter (68) electrically in parallel (STPC2) and connecting them to the first main power source (65).

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